Electrolysis device

ABSTRACT

The present invention provides an electrolyzing apparatus that includes a detector configured to detect an abnormality in a electrolytic bath and thereby enables a quick detection of the occurrence of the abnormality and that is less prone to a malfunction in which, due to an environmental change, a normal state is misjudged as abnormal and electrolysis is stopped. An electrolyzing apparatus of the present invention includes an electrolyzing section and a detecting section, the electrolyzing section being configured to receive an electrolytic substance, electrolyze the electrolytic substance to obtain an electrolysis product, and discharge the electrolysis product. The electrolyzing section includes electrolysis electrodes. The detecting section includes a detection electrode configured to measure an electrical property of either one of or a mixture of both of the electrolytic substance and the electrolysis product and is configured to detect a decrease in amount of the electrolytic substance supplied to the electrolyzing section or a decrease in amount of the electrolysis product discharged from the electrolyzing section.

TECHNICAL FIELD

The present invention relates to an electrolyzing apparatus.

BACKGROUND ART

Electrolyzing apparatuses are capable of converting various electrolytes into different substances through electrochemical reactions. For instance, electrolysis of an aqueous solution containing chloride ions gives an aqueous solution containing hypochlorous acids, i.e., so-called electrolyzed water. The electrolyzed water has the ability to eliminate bacteria and thus has been used for the purposes of preventing infectious diseases, keeping perishable food fresh, deodorizing laundry, and the like.

Electrolyzing apparatuses for producing electrolyzed water are known (refer to Patent Literatures 1 to 6, for example).

CITATION LIST Patent Literature

[Patent Literature 1]

Japanese Patent Application Publication, Tokukaihei, No. 4-74879

[Patent Literature 2]

Japanese Patent Application Publication, Tokukaihei, No. 5-237478

[Patent Literature 3]

Japanese Patent Application Publication, Tokukaihei, No. 6-292892

[Patent Literature 4]

Japanese Patent Application Publication, Tokukaihei, No. 9-253650

[Patent Literature 5]

Japanese Patent Application Publication, Tokukai, No. 2001-29955

[Patent Literature 6]

Japanese Patent Application Publication, Tokukai, No. 2001-48199

SUMMARY OF INVENTION Technical Problem

Electrolyzing apparatuses are capable of producing functional substances more easily and safely than chemical plants or the like which use normal chemical reactions. However, if an irregular electrolyte is accidentally supplied or the supply of an electrolyte stops for some reason, an unexpected substance may generate. To address this issue, there has been an electrolyzing apparatus designed to monitor voltage and current applied to electrolysis electrodes and, upon detecting a value other than a predetermined value, stop electrolysis. For instance, an abnormality can be detected in the following manner.

Provided that the electrolyzing apparatus is supplied with a constant voltage and the other parameters are kept constant, the resulting current value should be always the same. Therefore, if the current value has become larger or smaller than a certain value, then this can be determined as abnormal.

However, even with the same electrolyte and the same applied voltage, the current value may vary with changes in environmental temperature, i.e., changes in the temperature of the electrolyte. The current value may also be different between the initial stage of electrolysis and some point in time after the initial stage of the electrolysis. Therefore, it is necessary to set a relatively large allowable range for current value fluctuation.

In a case where the allowable range of current value is large like above, if the supply of solution has stopped for some reason, the following may occur before the current value exceeds the allowable range and the electrolysis stops. The liquid temperature may rise to around the heatresistant temperature of the electrolytic bath and cause deformation and, in the worst case, the electrolytic bath, which stores therein liquid and electrodes and the like, may be broken and may cause leakage of very hot electrolyzed water or leakage of gas generated in the electrolytic bath.

Especially in a case of an electrolytic bath for producing hypochlorous acid, the electrolytic bath is composed of resin and therefore has a relatively low heatresistant temperature, and thus is at high risk of deformation and breakage.

Furthermore, in a case of an apparatus designed to supply an undiluted solution (electrolyte) substantially continuously to the electrolytic bath to thereby continuously produce electrolyzed water, the inner volume of the electrolytic bath is smaller and current density is greater than a so-called reservoir electrolytic bath designed to reserve diluted electrolyte therein and perform electrolysis over time, and therefore the liquid temperature rises rapidly after the supply of the solution has stopped and overheating is likely to occur.

Especially in a case where the amount of an undiluted solution supplied to the electrolytic bath per unit time is kept small for the purpose of saving the undiluted solution, the liquid temperature becomes relatively high even in the steady state and therefore the temperature readily exceeds the heatresistant temperature of the electrolytic bath, resulting in lack of safety.

In view of the circumstances, the present invention provides an electrolyzing apparatus that includes a detecting section configured to detect an abnormality in a electrolytic bath and thereby enables a quick detection of the occurrence of the abnormality and that is less prone to a malfunction in which, due to an environmental change, a normal state is misjudged as abnormal and electrolysis is stopped.

Solution to Problem

The present invention provides an electrolyzing apparatus including an electrolyzing section and a detecting section, the electrolyzing section being configured to receive an electrolytic substance, electrolyze the electrolytic substance to obtain an electrolysis product, and discharge the electrolysis product, the electrolyzing section including electrolysis electrodes, and the detecting section including a detection electrode configured to measure an electrical property of either one of or a mixture of both of the electrolytic substance and the electrolysis product and being configured to detect a decrease in amount of the electrolytic substance received by the electrolyzing section or a decrease in amount of the electrolysis product discharged from the electrolyzing section.

The above-provided electrolyzing apparatus may be arranged such that the detection electrode is positioned higher than the electrolysis electrodes.

The above-provided electrolyzing apparatus may be arranged such that the detection electrode is positioned upstream of the electrolysis electrodes.

The above-provided electrolyzing apparatus may be arranged such that the detection electrode is disposed in, on, or at the electrolyzing section or a pipe connected to the electrolyzing section so as to be downstream of the electrolysis electrodes.

The above-provided electrolyzing apparatus may be arranged such that: the detection electrode includes at least one pair of electrodes; and one of the at least one pair of electrodes of the detection electrode is electrically connected to either one of the electrolysis electrodes.

The above-provided electrolyzing apparatus may be arranged such that: the detection electrode includes at least one pair of electrodes; and one of the at least one pair of electrodes of the detection electrode is integral with either one of the electrolysis electrodes.

The above-provided electrolyzing apparatus may be arranged such that the electrolysis electrodes and the detection electrode are inclined.

The above-provided electrolyzing apparatus may be arranged such that: the electrolytic substance is an electrolytic solution; and the electrolyzing section is configured to electrolyze the electrolytic solution to produce electrolyzed water containing hypochlorous acids.

The above-provided electrolyzing apparatus may be arranged such that the detection electrode is arranged to measure an electrical property of a gas-liquid mixture fluid composed of the electrolyzed water and a gas which are produced from electrolysis of the electrolytic solution.

Also provided is an electrolyzing apparatus arranged such that the detecting section is configured to detect, on the basis of the amount of change over time in a relationship between a current through the electrolysis electrodes and a voltage across the electrolysis electrodes, a decrease in amount of the electrolytic substance received by the electrolyzing section.

The above-provided electrolyzing apparatus may be arranged such that the detecting section is configured to detect, on the basis of a derivative value of the amount of change in the voltage across the electrolysis electrodes or on the basis of a derivative value of the amount of change in the current through the electrolysis electrodes, a decrease in amount of the electrolytic substance received by the electrolyzing section.

The present invention provides an electrolyzing apparatus including an electrolyzing section and a detecting section, the electrolyzing section being configured to electrolyze an electrolytic substance, the electrolyzing section including electrolysis electrodes, and the detecting section being configured to detect, on the basis of the amount of change over time in a relationship between a current through the electrolysis electrodes and a voltage across the electrolysis electrodes, a decrease in amount of the electrolytic substance supplied to the electrolyzing section.

The above-provided electrolyzing apparatus may be arranged such that the detecting section is configured to detect, on the basis of a derivative value of the amount of change in the voltage across the electrolysis electrodes or on the basis of a derivative value of the amount of change in the current through the electrolysis electrodes, a decrease in amount of the electrolytic substance supplied to the electrolyzing section has decreased.

Advantageous Effects of Invention

An electrolyzing apparatus of the present invention includes a detecting section. Therefore, with the detecting section, the electrolyzing apparatus is capable of detecting a decrease in the amount of an electrolytic substance received by an electrolyzing section, and is capable of stopping the application of a voltage to electrolysis electrodes early. This prevents the situation in which a voltage is applied to electrolysis electrodes that are not in contact with the electrolytic substance. This makes it possible to prevent abnormal overheating of the electrolysis electrodes and thus possible to improve safety of the electrolyzing apparatus. It is also possible to reduce damage to the electrolysis electrodes and thus possible to extend the life of the electrolyzing apparatus.

The electrolyzing apparatus of the present invention includes a detector which is capable of more quickly detecting an abnormality than before. Therefore, it is possible to provide a safe, highly-reliable electrolyzing apparatus.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic cross-sectional view of an electrolyzing apparatus of one embodiment of the present invention (Embodiment 1).

(a) to (e) of FIG. 2 are partial cross-sectional views illustrating an electrolyzing apparatus of one embodiment of the present invention.

FIG. 3 illustrates Detection System A (Embodiment 2).

FIG. 4 illustrates Detection System B (Embodiment 3).

FIG. 5 illustrates Detection System B (Embodiment 3).

FIG. 6 illustrates Detection System B (Embodiment 3).

FIG. 7 illustrates Detection System C (Embodiment 4).

FIG. 8 illustrates Detection System C (Embodiment 4).

FIG. 9 illustrates Detection System D (Embodiment 5).

FIG. 10 illustrates Detection System D (Embodiment 5).

FIG. 11 illustrates angles of inclination of an electrolyzing section and a detection system.

FIG. 12 is a partial cross-sectional view schematically illustrating an electrolyzing apparatus of one embodiment of the present invention (Embodiment 6).

FIG. 13 is a graph illustrating the results of a detection experiment on electrolyzed water.

FIG. 14 is another graph illustrating the results of a detection experiment on electrolyzed water.

FIG. 15 is a graph illustrating the results of measurement of effective chlorine concentration.

DESCRIPTION OF EMBODIMENTS

An electrolyzing apparatus of the present invention includes an electrolyzing section and a detecting section. The electrolyzing section is configured to receive an electrolytic substance, electrolyze the electrolytic substance to obtain an electrolysis product, and discharge the electrolysis product. The electrolyzing section includes electrolysis electrodes, and the detecting section includes a detection electrode configured to measure an electrical property of the electrolytic substance or the electrolysis product and is configured to detect a decrease in amount of the electrolytic substance received by the electrolyzing section.

An electrolyzing apparatus of the present invention includes an electrolyzing section and a detecting section. The electrolyzing section is configured to electrolyze an electrolytic substance. The electrolyzing section includes electrolysis electrodes, and the detecting section is configured to detect, on the basis of the amount of change over time in a relationship between a current through the electrolysis electrodes and a voltage across the electrolysis electrodes, a decrease in amount of the electrolytic substance received by the electrolyzing section.

The electrolyzing apparatus of the present invention is preferably arranged such that: the electrolytic substance is an electrolytic solution; and the electrolyzing section is configured to electrolyze the electrolytic solution to produce electrolyzed water containing hypochlorous acids.

It is preferable that the electrolytic solution electrolyzed in the electrolyzing section is an aqueous solution containing an acidic substance and an alkali metal chloride.

This makes it possible to produce electrolyzed water containing hypochlorous acids. The above configuration also makes it possible to produce slightly acidic to neutral electrolyzed water having a great bacteria elimination property.

It is preferable that the acidic substance contained in the electrolytic solution electrolyzed in the electrolyzing section is hydrochloric acid, and that the alkali metal chloride contained in the electrolytic solution is at least one of sodium chloride and potassium chloride.

This makes it possible to produce electrolyzed water containing hypochlorous acids. The above configuration also makes it possible to produce slightly acidic to neutral electrolyzed water having a great bacteria elimination property. The obtained electrolyzed water also has a high effective chlorine concentration.

It is preferable that an electrolyzed water producing section included in an electrolyzing apparatus of the present invention includes: an electrolytic solution supplying section; an electrolyzing section configured to receive an electrolytic solution from the electrolytic solution supplying section and electrolyze the electrolytic solution to produce electrolyzed water; and a diluting section configured to dilute the electrolyzed water produced by the electrolyzing section.

Such an arrangement makes it possible to continuously produce electrolyzed water having an adequate effective chlorine concentration. Furthermore, since the electrolyzed water produced by the electrolyzing section is diluted by the diluting section, a large amount of electrolyzed water can be produced.

An electrolyzing apparatus of the present invention is preferably arranged such that: an electrolytic solution supplying section is configured to supply an electrolytic solution from a tank to the electrolyzing section; the electrolyzing section includes an electrolysis electrode pair to electrolyze the electrolytic solution to produce electrolyzed water; and a detecting section is positioned downstream of the electrolysis electrode pair and is configured to detect a decrease in the amount of the electrolytic solution supplied from the electrolytic solution supplying section to the electrolyzing section.

According to such an arrangement, the electrolyzing apparatus is capable of detecting, with the detecting section, a situation in which the tank has become empty, and thus is capable of stopping the application of a voltage to the electrolysis electrode pair early. This reduces damage to the electrolysis electrode pair.

The detecting section included in the electrolyzing apparatus of the present invention preferably includes a detection electrode, and the detection electrode is preferably arranged to measure an electrical property of a gas-liquid mixture fluid composed of gas and electrolyzed water which are produced from electrolysis of an electrolytic solution.

This configuration enables detection of, with the use of the detection electrode, whether or not the electrolyzed water is being produced in the electrolyzing section.

The electrolyzing apparatus of the present invention preferably further includes a cooling section for cooling the electrolyzing section, and the cooling section is preferably configured to cool the electrolyzing section with water for use in diluting the electrolyzed water.

Such an arrangement prevents or reduces temperature rise in the electrolyzing section that would result from the heat of the electrolysis reaction, and therefore the following cases are prevented or reduced, for example: electrolysis efficiency varies and thereby variations occur in concentration; constituents of the electrolyzing section deform or deteriorate due to overheating of the electrolyzing section and thus troubles occur such as liquid leakage; and the like.

It is preferable that an electrolyzing apparatus of the present invention includes a detecting section and that an electrolytic solution supplying section is configured to supply an electrolytic solution from a tank to the electrolyzing section, the electrolyzing section includes an electrolysis electrode pair configured to electrolyze the electrolytic solution to produce electrolyzed water, and the detecting section is positioned downstream of the electrolysis electrode pair and is configured to detect a decrease in the amount of the electrolytic solution supplied from the electrolytic solution supplying section to the electrolyzing section.

According to such an arrangement, the electrolyzing apparatus is capable of detecting, with the detecting section, a situation in which the supply of the electrolytic solution to the electrolytic bath has stopped for some reason or the inside of the electrolytic bath has entered an abnormal state due to, for example, liquid leakage, and is thus capable of stopping the application of a voltage to the electrolysis electrode pair early. This makes it possible to reduce damage to the electrolysis electrode pair.

It is also possible to stop the electrolyzing section early and notify users of the abnormal condition using a visual indicator or buzzer. This makes it possible to prevent electrolyzed water having an undesired concentration or an undesired pH from being used in bacteria elimination. For example, the following can be prevented: the amount of the electrolytic solution supplied is too small and the concentration of the electrolyzed water becomes lower than desired or the pH of the electrolyzed water becomes higher (becomes more alkaline) than desired and thus bacteria elimination becomes not satisfactory; and the amount of the electrolytic solution supplied is too much and the concentration of the electrolyzed water becomes higher than desired or the pH of the electrolyzed water becomes lower (becomes more acidic) than desired and therefore fibers are damaged or decolored.

The detecting section included in the electrolyzing apparatus of the present invention preferably includes a detection electrode, and the detection electrode is preferably arranged to measure an electrical property of a gas-liquid mixture fluid composed of gas and electrolyzed water which are produced from electrolysis of an electrolytic solution.

This configuration enables detection of, with the use of the detection electrode, whether or not the electrolyzed water is being produced in the electrolyzing section.

The electrolyzing apparatus of the present invention preferably further includes a cooling section for cooling the electrolyzing section, and the cooling section is preferably configured to cool the electrolyzing section with water for use in diluting the electrolyzed water.

Such an arrangement prevents or reduces temperature rise in the electrolyzing section that would result from the heat of the electrolysis reaction, and thus the following cases are prevented or reduced, for example: electrolysis efficiency varies and thereby variations occur in concentration; the electrolyzing section is overheated and deformed and thus troubles occur such as liquid leakage; and the like. Even if, by any chance, a detector is broken and becomes overheated, cooling of the electrolyzing section prevents or reduces the occurrence of fire or smoke from the electrolyzing section and prevents or reduces troubles that would result from heat transmitted to other constituents around the electrolyzing section.

The present invention can be used not only for an electrolyzing apparatus to electrolyze an aqueous solution but also for various apparatuses to convert a substance disposed between electrodes into a different substance by applying a voltage across the electrodes. For instance, not only a liquid but also a gas can be converted into a different substance by applying a voltage to the gas, i.e., by means of so-called electric discharge. In this specification, such an apparatus for conversion is referred to as a substance conversion apparatus, electrodes for use in the substance conversion are referred to as substance conversion electrodes, a substance to be converted is referred to as a to-be-converted substance or an unconverted substance, and an produced substance is referred to as a resultant substance or a converted substance.

A substance conversion apparatus of the present invention is an apparatus for converting a substance (unconverted substance) into a different substance (converted substance) different than the unconverted substance by supplying the unconverted substance between a pair of substance conversion electrodes and applying a voltage. The substance conversion apparatus includes a detection system configured to detect an abnormality by: applying a constant voltage across the substance conversion electrodes and monitoring the value of a current through the substance conversion electrodes; or carrying out a control so that the current is kept constant and monitoring the value of the voltage necessary for a certain current to flow through the electrodes, as well as distinguishing between abnormal and normal states using a parameter other than the values of the current and the voltage applied to the substance conversion electrodes.

The present invention provides a detector and a detection system which are for discriminating between normal and abnormal states by detecting the state of an apparatus (substance conversion apparatus) for converting a substance into another substance by applying a voltage to the substance. The substance conversion apparatus is capable of, for example, converting any of various substances into a different substance by applying electric energy to the substance between substance conversion electrodes to thereby cause any of various chemical reactions, and thereby, for example, producing a useful substance or rendering toxic substances harmless. An easy-to-understand example of the substance conversion apparatus is an electrolyzing apparatus.

Conventional apparatuses are arranged such that a constant voltage is applied across the substance conversion (electrolysis) electrodes and the value of a current through the electrodes is monitored (alternatively, a current is controlled at a certain value and the value of a voltage necessary for the current of the certain value to flow through the electrodes is monitored). The voltage and current should become constant, provided that the conditions for substance conversion and outside environmental conditions are constant. Therefore, by setting a voltage range or a current range under the normal steady state, it is possible to determine that an abnormality has occurred when the set range (allowable range) is exceeded. This method has been used conventionally. However, this method has an issue in that, if the set range is too narrow (process window is too narrow), the apparatus readily stops depending on the environment (outside environment such as temperature), component tolerance of the apparatus, changes in conditions as substance conversion proceeds, and the like and therefore is not practical. In view of such circumstances, wide allowable ranges have been used. However, with a wide allowable range, the time from the start of an abnormality to the detection of the abnormality may become long. This may cause a trouble in the apparatus or defects in products (resulting substances).

The present invention provides a detector and a detection system which are capable of, when an abnormality has occurred, quickly and accurately determining that the abnormality has occurred.

The detection system of the present invention detects an abnormality by distinguishing between normal and abnormal states of a second value that is other than the values of a voltage and a current applied to substance conversion electrodes.

A substance conversion electrode may also serve as the detection electrode. This reduces parts count and leads to cost reduction, and therefore the apparatus becomes more practical.

The present invention is more preferably arranged such that the electrolytic bath is inclined, because this improves detectability.

The present invention is more preferably arranged such that the electrolytic bath includes a cooling system, especially a water-cooling system.

The following description will discuss an embodiment of the present invention with reference to the drawings. The configurations illustrated in the drawings or described below are mere examples. The present invention is not limited in scope to the configurations illustrated in the drawings or described below.

Examples of an electrolyzing apparatus of the present embodiment include electrolyzing apparatuses of Embodiments 1 to 6. FIG. 1 is a schematic cross-sectional view of the electrolyzing apparatus of Embodiment 1.

An electrolyzing apparatus 60 of the present embodiment includes: an electrolyzing section 5 configured to receive an electrolytic substance, electrolyze the electrolytic substance to obtain an electrolysis product, and discharge the electrolysis product; and a detecting section 25. The electrolyzing section 5 includes electrolysis electrodes 1. The detecting section 25 includes a detection electrode 26 arranged to measure an electrical property of the electrolytic substance or the electrolysis product and is configured to detect a decrease in the amount of the electrolytic substance supplied to the electrolyzing section 5. That is, the detecting section 25 is a detection circuit that includes the detection electrode 26 and other electronic components.

Alternatively, the electrolyzing apparatus 60 of the present embodiment includes: an electrolyzing section 5 configured to electrolyze an electrolytic substance; and a detecting section 25. The electrolyzing section 5 includes electrolysis electrodes 1. The detecting section 25 is configured to detect, on the basis of the amount of change over time in a relationship between a current through the electrolysis electrodes 1 and a voltage across the electrolysis electrodes 1, a decrease in amount of the electrolytic substance received by the electrolyzing section 5.

The electrolytic substance may be any substance, provided that it can be electrolyzed by the electrolyzing section 5. The electrolytic substance may be an electrolytic solution. Alternatively, the electrolytic substance may be a gas that can be electrolyzed by the electrolyzing section 5. The following describes the electrolyzing apparatus 60 in which the electrolytic substance is an electrolytic solution 12 and which is configured to produce electrolyzed water 18 from the electrolytic solution 12 in the electrolyzing section 5.

An electrolyzed water producing section 2 serves to produce the electrolyzed water 18 from the electrolytic solution 12.

The electrolyzed water producing section 2 may include: an electrolytic solution supplying section 10; an electrolyzing section 5 configured to electrolyze an electrolytic solution 12 supplied from the electrolytic solution supplying section 10 to produce electrolyzed water 18; and a diluting section 20 configured to dilute the electrolyzed water 18 produced by the electrolyzing section 5.

The electrolytic solution supplying section 10 may be configured to supply the electrolytic solution 12 in an electrolytic solution tank 7 to the electrolyzing section 5 with the use of a pump 8. The electrolytic solution tank 7 may be built in the electrolyzing apparatus 60 or may be external to the electrolyzing apparatus 60. In a case where the electrolytic solution tank 7 is external to the electrolyzing apparatus 60, the electrolyzing apparatus 60 may have an electrolytic solution inlet 42. This enables connection between the electrolytic solution inlet 42 and the externally provided electrolytic solution tank 7 through a pipe. The electrolytic solution supplying section 10 may include a large-volume electrolytic solution tank 7 and/or a normal-volume electrolytic solution tank 7. This makes it possible to change the volume of the electrolytic solution tank 7 according to the use of the electrolyzing apparatus 60.

It is noted that, in a case where the electrolytic solution tank 7 can be positioned higher than the electrolyzing section 5 so that the electrolytic solution 12 will be supplied to the electrolyzing section 5 with the force of gravity, a valve may be used in place of the pump 8.

The electrolyzing section 5 serves to electrolyze the electrolytic solution 12 to thereby produce the electrolyzed water 18. The electrolyzing section 5 may include electrolysis electrodes 1 including a positive electrode 3 and a negative electrode 4. The electrolyzing section 5 may be provided in such a manner that the electrolytic solution 12 is supplied between the electrolysis electrode pair 1 by the electrolytic solution supplying section 10. This makes it possible to continuously produce the electrolyzed water 18 from the electrolytic solution 12.

The electrolytic solution 12, which is supplied to the electrolyzing section 5 by the electrolytic solution supplying section 10, may be an aqueous solution containing an acidic substance and an alkali metal chloride. The electrolytic solution 12 may be an aqueous solution containing hydrochloric acid and at least one of sodium chloride and potassium chloride. This enables the electrolyzing section 5 to produce electrolyzed water 18 containing hypochlorous acid (HClO), a hypochlorite (NaClO, KClO, or the like) and an alkali metal chloride.

For instance, it is apparent that the electrolysis process in the electrolyzing section 5 involves an anodic reaction such as those represented in Reaction Formulae (1) and (3) and a cathodic reaction such as that represented in Reaction Formula (4). It is also apparent that the reaction such as that represented in Reaction Formula (2) proceeds inside the electrolyzing section 5, the diluting section 20, an electrolyzed water channel, a stirring section 19, and/or the like. Therefore, the electrolyzed water 18 which has just been produced through electrolysis from the electrolytic solution in the electrolyzing section 5 is in the form of a fluid of a mixture of gas and liquid, in which bubbles of chlorine gas, hydrogen gas, and the like are mixed in the electrolyzed water containing chlorine molecules, hydrogen molecules, and the like. As a reaction such as that represented in Reaction Formula (2) proceeds, the number of bubbles decreases, and the concentration of hypochlorous acids in the electrolyzed water increases. Since the reaction of Reaction Formula (2) proceeds relatively rapidly, many of the chlorine molecules generated react to form hypochlorous acids in the electrolyzing section 5. Unreacted chlorine molecules are subjected to a large amount of water (H₂O) in the diluting section 20. Bubbles of chlorine gas disappear almost entirely during a flow through the electrolyzed water channel.

2Cl⁻->Cl₂+2e ⁻  (1)

Cl₂+H₂O->HCl+HClO  (2)

H₂O->½O₂+2H⁺+2e ⁻  (3)

2H₂O+2e ⁻->H₂+2OH⁻  (4)

Electrolyzing an aqueous solution containing an alkali metal chloride may generate a hypochlorite such as sodium hypochlorite and/or potassium hypochlorite and make the electrolyzed water 18 alkaline. However, since the electrolytic solution 12 of the present embodiment contains an acidic substance, the electrolyzed water 18 is substantially neutral.

Electrolyzed water 18 produced by the electrolyzing apparatus 60 may have a pH of, for example, 6.5 to 7.5. The ratio between an alkali metal chloride and the acidic substance for the electrolytic solution 12 may be adjusted so that the electrolyzed water 18 will have a pH of 6.5 to 7.5.

Further, in a case where the pH is to be lower, the pH of the electrolyzed water 18 may be adjusted by adjusting, for example, (i) the proportion of the acidic substance in the electrolytic solution 12, (ii) the amount of the electrolytic solution 12 supplied to the electrolyzing section 5, (iii) the voltage applied to the electrolysis electrodes 1, and/or (iv) the amount of the electric current flowing through the electrolysis electrodes 1.

The electrolyzing section 5 may have: an inlet through which the electrolyzing section 5 receives the electrolytic solution 12 supplied from the electrolytic solution supplying section 10; and an outlet through which the electrolyzing section 5 discharges the electrolyzed water 18 produced through electrolysis with the use of the electrolysis electrode pair 1. This enables the electrolyzing section 5 to continuously produce the electrolyzed water 18. The electrolyzed water 18 discharged through the outlet may flow into the diluting section 20.

The positive electrode 3 and the negative electrode 4 may be in the form of a plate, and may be disposed so as to face each other with no diaphragm in-between. This shortens the distance between the electrodes and improves electrolysis efficiency. The positive electrode 3 and the negative electrode 4 may be disposed in substantially parallel to each other at a distance of 1 mm to 5 mm from each other.

The electrolysis electrode pair 1 may be constituted by: one positive electrode 3 and one negative electrode 4 facing each other; positive electrodes 3 and negative electrodes 4 alternately stacked together with spaces between them; or a plurality of electrodes stacked together in which an intermediate electrode has one surface serving as a positive electrode 3 and the other surface serving as a negative electrode 4.

The electrode pair 1 may be inclined in a manner such that the positive electrode 3 is positioned higher than the negative electrode 4. FIG. 11 illustrates an inclined electrode pair 1 of the electrolyzed water producing apparatus 60 of the present embodiment.

The electrolytic solution channel defined by an electrode surface of the positive electrode 3 and an electrode surface of the negative electrode 4 may be arranged such that the electrolytic solution 12 flows into the electrolytic solution channel from below and that the electrolyzed water containing hypochlorous acids, produced through electrolysis of the electrolytic solution 12 with the use of the electrode pair 1, flows out of the electrolytic solution channel from an upper portion of the electrolytic solution channel. It is apparent that, with this configuration, a flow of a fluid which flow is caused by rising bubbles generated on the electrode surface of the negative electrode 4 causes a fluid in the vicinity of the negative electrode 4 and a fluid in the vicinity of the positive electrode 3 to be stirred and mixed with each other, presumably accelerating an electrode reaction at the positive electrode 3. This in turn makes it possible to produce electrolyzed water containing effective chlorine at a high concentration.

It is also apparent that the negative electrode 4, which is positioned lower than the positive electrode 3 to cause a flow from the negative electrode 4 toward the positive electrode 3, makes it possible to suppress the oxidation of the electrode surface of the negative electrode 4 that would occur due to chlorine gas, oxidizing substances, hypochlorous acid, or the like produced from the anodic reaction, and thus possible to efficiently produce electrolyzed water containing hypochlorous acids. Furthermore, since the oxidation of the electrode surface of the negative electrode 4 is suppressed, a Ti electrode may be used as the negative electrode 4, and this makes it possible to reduce production cost of the electrolyzing apparatus 60.

Furthermore, when the negative electrode 4 is positioned lower than the positive electrode 3, the hydrogen gas generated from the cathodic reaction readily detaches from the electrode surface of the negative electrode 4. This prevents or reduces a decrease in effective area of the negative electrode that would occur due to bubbles staying on the electrode surface of the negative electrode 4, and thus makes it possible to prevent or reduce a decrease in electrolysis efficiency. Further, in a case where the negative electrode 4 is a Ti electrode, the above configuration can prevent the negative electrode 4 (Ti electrode) from occluding hydrogen molecules and being warped in consequence.

The electrode pair 1 may be inclined at an angle of not less than 10 degrees and not more than 85 degrees relative to the vertical direction. The electrode pair 1 should preferably be inclined at an angle of not less than 50 degrees and not more than 80 degrees relative to the vertical direction. This makes it possible to efficiently produce electrolyzed water containing hypochlorous acids. This has been substantiated by experiments conducted by the inventors of the present invention. Since the electrode pair 1 is inclined sufficiently, it is possible to produce an electrolyzing apparatus 60 that has a small height and that can be installed stably. With the above configuration, the electrolyzing apparatus 60 has a reduced risk of toppling over, for example.

The positive electrode 3 should preferably have a substantially rectangular electrode surface and be oriented in such a manner that one lengthwise end of the electrode surface is positioned higher than the other lengthwise end. The negative electrode 4 should preferably have a substantially rectangular electrode surface and be oriented in such a manner that one lengthwise end of the electrode surface is positioned higher than the other lengthwise end. This configuration provides a long electrolytic solution channel, thereby increasing the electrolysis efficiency.

The electrode pair 1 should preferably be configured such that the ratio of (i) the distance between the positive electrode 3 and the negative electrode 4 to (ii) the length of the electrode surface of the positive electrode 3 or the electrode surface of the negative electrode 4 is within a range of 1:100 to 1:10. This configuration allows bubbles generated by a cathodic reaction to rise to be close to the positive electrode 3, thereby increasing the electrolysis efficiency.

The electrolysis electrode pair 1 may include, for example, an electrode constituted by a titanium plate (such an electrode is referred to as a Ti electrode) and an electrode obtained by coating a titanium plate with iridium and platinum through a sintering process (such an electrode is referred to as a Pt—Ir-coated Ti electrode). The power source section 6 and the electrolysis electrode pair 1 may be connected in such a manner that the Ti electrode serves as the negative electrode 4 and the Pt—Ir-coated Ti electrode serves as the positive electrode 3.

The electrolyzing apparatus 60 may include a detecting section 25 on the downstream side of the electrolysis electrode pair 1. The detecting section 25 serves to detect a decrease in the amount of the electrolytic solution 12 supplied from the electrolytic solution supplying section 10 to the electrolyzing section 5. The detecting section 25 may be disposed at a position higher than the position of the electrolysis electrode pair 1.

The detecting section 25 may be in the form of (i) a detection electrode(s) 26 for measuring electrical properties of electrolyzed water 18 (such as the current, voltage, resistance, and/or capacitance) or (ii) a photodetector section configured to optically detect the state of electrolyzed water 18. However, the detecting section 25 is preferably a detection electrode(s) because this achieves a simple system. It may seem easy to use a method for measuring or optically detecting a capacitance because such a method will not involve contact with electrolyzed water and thus eliminate the need to consider the impacts of electrolyzed water. However, using such a method will require a special component and/or control circuit as a separate member. In the case of a detection electrode(s), suitable conditions for the voltage, current, and the like vary depending on the target. Further, common knowledge of persons skilled in the art is that in a case where an electrolytic solution, which contains an electrolyte, is a target for the present invention, it will be difficult to detect the state of electrolyzed water with use of electrodes. Using electrodes as such has not been practiced as a result. Specifically, the electrolytic solution will be electrolyzed by a voltage or current for detection, which will in turn make it impossible to measure electrical properties of the electrolytic solution itself. Further, in a case where electrolysis produces a reactive liquid as electrolyzed water (for example, an oxidative liquid such as hypochlorous acid water and hypochlorite water), the electrodes themselves will presumably be oxidized and changed. In view of such observations, a detection electrode(s) was/were regarded as lacking stability and/or a practical life. It was thus believed to be difficult to use electrodes as an inexpensive, long-life detector to be mounted in a producing apparatus for a long-term, constant use. The inventors actually needed to select an appropriate position for the electrode(s) and an appropriate size for a channel at the electrode position, and thus had difficulty arriving at the present invention. For instance, in order to dispose electrode(s) on the channel, the inventors secured a detection area in which the channel had a relatively large cross-sectional area. This configuration, however, caused the gas and the liquid to be separated from each other and failed to form a liquid membrane, with the result that it was impossible to detect a liquid (that is, a liquid membrane between bubbles) effectively. When the inventors reduced the channel diameter to a relatively small length to prevent the liquid membrane from being cut off or disposed the electrodes with a relatively small distance therebetween, surface tension kept a liquid membrane between the electrodes, with the result that no bubbles were detected. In either case, no clear current peak was detected, and it was impossible to distinguish between the steady state and an abnormal state early.

In a case where an electrolytic solution 12 in the tank 7 is supplied to the electrolyzing section 5 with use of the pump 8 for production of electrolyzed water 18, continuing the production of the electrolyzed water 18 gradually decreases the electrolytic solution 12 in the tank 7 and finally empties the tank 7. The emptied tank 7 stops the supply of the electrolytic solution 12 to the electrolyzing section 5, with the possible result that the electrolytic solution 12 between the electrode pair 1 is decreased or disappears. The electrolytic solution 12 between the electrode pair 1 may be decreased or disappear not only in the case where the tank 7 has been emptied, but also in a case where the pump 8 has broken down or there is liquid leakage between the tank 7 and the electrolyzing section 5, so that the electrolytic solution 12 is not supplied to the electrolyzing section 5 sufficiently. Applying a voltage to the electrode pair 1 in such a state leads to (i) an increase in heat in the electrolyzing section 5 as a result of a lack of a cooling effect by a continuously supplied electrolytic solution and a lack of heat dissipated together with produced electrolyzed water and/or (ii) in the case of a constant current, an increase in electric current density as a result of an electric current flowing through only a part of the electrodes. As a result, the electrolyzing section 5 and/or the electrode pair 1 may be damaged. This indicates the need to detect whether the supply of the electrolytic solution 12 between the electrode pair 1 is insufficient and stop applying a voltage to the electrode pair 1 as necessary.

By monitoring a voltage and/or a current supplied to the electrode pair 1, it is possible to detect an abnormality in the electrolytic solution 12 between the electrode pair 1, and thus possible to detect stoppage or insufficiency of supply. In a normal state in which normal supply continues, the voltage and current are substantially constant, provided that the other parameters are kept constant.

Provided that the electrode pair 1 is supplied with power at a constant voltage from a common power source or from a power source for electrolysis, the stoppage or insufficiency of supply will lead to a temperature rise, which accelerates an electrolysis reaction and increases current value. Then, a boiling state is reached, in which many bubbles generate and hinder current flow. This results in lowering of current value. If the electrolytic solution present between the electrode pair 1 is lost by evaporation, the current flow will stop. In view of this, the following arrangement may be employed: current value is monitored and, if the current value becomes equal to or greater than a certain value, overheating is determined to have occurred and voltage application is stopped. Alternatively, the following arrangement may be employed: voltage application is stopped earlier by, if the rate of increase in current has become equal to or greater than a certain value from which the amount of change in current value can be calculated, determining that an abnormal temperature rise has started and stopping the voltage application.

Provided that power is supplied at a constant current, stoppage or insufficiency of supply will cause a temperature rise, which accelerates an electrolysis reaction and lowers voltage value, and thereafter causes a boiling state in which many bubbles generate and hinder current flow, resulting in an increase in voltage value. If the electrolytic solution present between the electrode pair 1 is lost by evaporation, no current flows even at the maximum voltage that can be applied by a constant-current source. In view of this, the following arrangement may be employed: voltage value is monitored and, if the voltage value becomes equal to or less than a certain value, overheating is determined to have occurred and voltage application is stopped. Alternatively, the following arrangement may be employed: voltage application is stopped earlier by, if the rate of decrease in voltage becomes equal to or greater than a certain value from which the amount of change in voltage value can be calculated, determining that an abnormal temperature rise has started and stopping the voltage application.

It is noted that constant current is more preferred, because constant current provides stable concentration of the electrolyzed water even when outside environment changes.

Including the detecting section 25 makes it possible to detect whether the tank 7 has been emptied, the pump 8 is malfunctioning, and/or there is leakage or clogging in the pipe between the tank and the electrolyzing section. This in turn makes it possible to stop the application of a voltage to the electrode pair 1 early. The above configuration thus prevents the electrode pair 1 from being damaged.

In a case where the tank 7 has become empty and the supply of the electrolytic solution 12 to the electrolyzing section 5 has become insufficient, the electrolytic solution 12 or electrolyzed water 18 starts to disappear first from a high portion of the channel. Thus, disposing the detecting section 25 at a position higher than the position of the electrode pair 1 makes it possible to detect early whether the supply of the electrolytic solution 12 to the electrolyzing section 5 has become insufficient.

(a) to (e) of FIG. 2 are partial cross-sectional views each schematically illustrating an electrolyzing apparatus 60 of the present embodiment. The detection electrode 26 may be, for example, (i) an electrode pair disposed in, on, or at a pipe between the electrolyzing section 5 and the diluting section 20 as illustrated in (a) of FIG. 2, (ii) an electrode pair disposed in the channel inside the electrolyzing section 5 as illustrated in (b) of FIG. 2, or (iii) an electrode pair disposed above the electrode pair 1 as illustrated in (c) of FIG. 2. The detecting section 25 may be configured such that one of the electrode pair 1 and a detection electrode 26 are used to measure electrical properties of electrolyzed water 18 as illustrated in (d) and (e) of FIG. 2.

Electrolyzing the electrolytic solution 12 with use of the electrode pair 1 involves chemical reactions such as those represented in Reaction Formulae (1) to (4). Electrolyzed water 18 produced with use of the electrode pair 1 is thus a fluid of a mixture of gas and liquid. In a case where the detection electrode(s) 26 is/are used to measure electrical properties of a fluid of a mixture of gas and liquid, bubbles passing by the detection electrode(s) 26 increase the electric resistance between the electrodes and thus increase the current flowing between the electrodes, whereas a liquid passing by the detection electrode(s) 26 decreases the electric resistance between the electrodes and thus decrease the current flowing between the electrodes. This indicates that in a case where electrolyzed water 18 is being produced normally with use of the electrode pair 1, properties measured with use of the detection electrode(s) 26 such as the electric resistance fluctuate. Detecting such a fluctuation thus makes it possible to learn that electrolyzed water 18 is being produced normally. Further, detecting a lack of such a fluctuation makes it possible to detect an abnormality such as an empty tank, a broken liquid flowing pump, a clogged pipe, and liquid leakage.

The detection electrodes 26 may be separated from each other by a distance of, for example, 1 mm to 5 mm. This configuration makes it possible to confirm the flow of electrolyzed water 18.

The example described here involves use of a detection electrode(s) 26 to detect a flow of electrolyzed water 18. The detecting section 25 may alternatively be a photodetector section configured to optically detect a flow of electrolyzed water 18.

FIG. 3 illustrates Detection System A included in an electrolyzing apparatus of the second embodiment. The detecting section 25 may include a system to detect an abnormality, like Detection System A. Detection System A has not only an allowable range (set value) for the voltage or current of the electrolysis electrodes 1, but also an allowable range for the amount of change over time in the voltage, current, or both of the electrolysis electrodes 1. The detecting section 25 is capable of detecting an abnormality on the basis of a derivative value (which refers to the average change amount per unit of time) of the voltage value or current value of the electrolysis electrodes 1. The detecting section 25 is, in this case, included in a control section 6. For other detection systems as well, including a detecting section in a control section is preferable because such a configuration can incorporate both sections in a single plated circuit and thereby achieve a smaller size and a lower cost.

For instance, electrodes for sensing are connected to a constant-current source or constant-voltage source, and are used to detect an abnormality by distinguishing the amount of change in the voltage value or current value between a normal state and an abnormal state within a certain period of time. An allowable range is set for the amount of change over time of the voltage, the current, or both. In other words, the detection electrodes are used to detect a derivative value of the voltage value or current value (the derivative value refers to the average change amount per unit of time and may also be expressed as a slope). The voltage value and the current value may be detected by a conventional method. A derivative value may be found by sampling the voltage value or current value at a fixed time interval(s) and calculating the voltage change over time. Sampling the voltage value or current value at an excessively short time interval will, however, lead to a false positive in abnormality detection as a result of noise, for example. It is thus preferable to (i) sample the voltage value or current value at a time interval of, for example, 10 seconds to 1 minute and (ii) calculate the difference between those samples.

The detection system described here includes sensing electrodes that utilize the derivative value being substantially zero in the steady state. For instance, disposing detection electrodes at a position that is closer to the supply opening for an electrolytic solution than the electrolysis electrodes are to the supply opening maintains the voltage-current relationship based on the electrical properties of the electrolytic solution. In a case where, for instance, the supply of an electrolytic solution has stopped abnormally, detection electrodes disposed at a position in the electrolytic bath which position is close to the supply opening for an electrolytic solution causes the current voltage-current relationship to become closer to the voltage-current relationship of electricity of electrolyzed water resulting from the electrolytic solution being electrolyzed with use of the electrolysis electrodes. During this process, the derivative value becomes non-zero. This allows the abnormality to be detected. In a case where sensing electrodes are disposed at a position that is even closer to the tank of an electrolytic solution than the electrolytic bath is to the tank, for instance, in a case where sensing electrodes are disposed in the pipe or on the pipe, an electrolytic solution in the vicinity of the sensing electrodes becomes electrolyzed with the sensing electrodes, and the derivative value becomes non-zero similarly. This allows the abnormality to be detected.

Disposing detection electrodes at a position that is closer to the discharge opening for an electrolytic solution than the electrolysis electrodes are to the discharge opening maintains the voltage-current relationship based on the electrical properties of the electrolyzed water. In a case where, for instance, the supply of an electrolytic solution has stopped abnormally, detection electrodes disposed at a position in the electrolytic bath which position is close to the discharge opening for an electrolytic solution causes the current voltage-current relationship to become closer to the voltage-current relationship of electricity of electrolyzed water resulting from the electrolytic solution being excessively electrolyzed with use of the electrolysis electrodes. During this process, the derivative value becomes non-zero. This allows the abnormality to be detected. In a case where sensing electrodes are disposed at a position that is even closer to the discharge opening for electrolyzed water than the electrolytic bath is to the tank, for instance, in a case where sensing electrodes are disposed in the pipe or on the pipe, electrolyzed water in the vicinity of the sensing electrodes becomes absent or further electrolyzed with the sensing electrodes, and the derivative value becomes non-zero similarly. This allows the abnormality to be detected.

Disposing detection electrodes at a position that is closer to the electrolysis electrodes maintains the voltage-current relationship based on the electrical properties of the electrolytic solution being electrolyzed. In a case where, for instance, the supply of an electrolytic solution has stopped abnormally, detection electrodes disposed at a position that is closer to the electrolysis electrodes causes the current voltage-current relationship to become closer to the voltage-current relationship of electricity of electrolyzed water resulting from the electrolytic solution being excessively electrolyzed with use of the electrolysis electrodes. During this process, the derivative value becomes non-zero. This allows the abnormality to be detected.

In a case where sensing electrodes are disposed in the electrolytic bath, part or all of the sensing electrodes may double as an electrolysis electrode, and may also be connected to a power source for electrolysis.

FIGS. 4 to 6 illustrate Detection System B included in an electrolyzing apparatus of the third embodiment. The detecting section 25 may include a system to detect an abnormality, like Detection System B. Detection System B includes, as the detecting section 25, a detection electrode(s) 26 different from the electrolysis electrodes 1. The detection electrode(s) 26 is/are disposed above the electrolysis electrodes 1. In a case where the supply of an electrolytic solution has stopped or become insufficient, the above configuration makes it possible to detect a change in, for example, electrical conductivity in the vicinity of the detection electrode(s) 26. Specifically, the detection electrode(s) 26 is/are used to detect a decrease in the current value which decrease has been caused by a lowered level of the electrolytic solution in the electrolyzing section 5. Although the detection section 25 may include a pair of electrodes 26 for the detection, using one of the electrolysis electrodes 1 for both the electrolysis and the detection reduces the parts count. Further using the power source section for both the electrolysis and the detection makes it possible to omit a power source for the detecting section. A lowered level of the electrolytic solution influences the electrolysis electrodes 1 as well; it decreases the current value or increases the voltage value as a result of a reduced effective area of the electrodes. However, the proportion of such a change (that is, the proportion of the change value to the total value), the S/N value, and the like are small. This causes a problem similar to those with conventional art. An abnormality can be detected by, for instance, slitting an upper portion of an electrolysis electrode(s) 1 for a partial separation, connecting a wire to the separated part, and measuring the value of the electric current flowing through the wire. The current value may be measured by any of various conventional methods such as a method of measuring the voltage of a shunt resistor.

FIGS. 7 and 8 illustrate Detection System C included in an electrolyzing apparatus of the fourth embodiment. The detecting section 25 may include a system to detect an abnormality, like Detection System C. In Detection System C, the detecting section 25 includes a detection electrode(s) 26 as a detector similarly to the above, the detection electrode(s) 26 being disposed at a position that is closer to the supply opening (that is, the electrolytic solution supply opening of the electrolyzing section) for an electrolytic substance (electrolytic solution) than the electrolysis electrodes 1 are to the supply opening. Using the above detection electrode(s) 26 to detect a difference between electrical properties of the electrolytic substance and those of an electrolysis product (electrolyzed water) makes it possible to detect whether the supply of the electrolytic substance (electrolytic solution) has stopped or become insufficient. The steady state leads the detecting section 25 to obtain values relatively close to those of the electrical properties of the electrolytic substance (electrolytic solution), whereas an abnormal state leads the detecting section 25 to obtain values relatively close to those of the electrical properties of the electrolysis product (electrolyzed water). This allows an abnormality to be detected.

FIGS. 9 and 10 illustrate Detection System D included in an electrolyzing apparatus of the fifth embodiment. The detecting section 25 may include a system to detect an abnormality, like Detection System D. In Detection System D, the detecting section 25 includes a detection electrode(s) 26 as a detector similarly to the above, the detection electrode(s) 26 being disposed (i) at a position (that is, the discharge opening of the electrolyzing section 5 for the case of electrolysis) that is closer to the discharge opening for an electrolysis product than the electrolysis electrodes are to the discharge opening, (ii) at the discharge opening, (iii) in or on a pipe connected to the discharge opening, or (iv) between pipes.

Using the above detection electrode(s) to detect a difference in electrical properties between the normal state (in which an electrolysis product [electrolyzed water] is being flown to the detector continuously) and a state that is not the normal state (in which electrolyzed water is not being flown to the detector continuously) makes it possible to detect whether the supply of the electrolytic substance (electrolytic solution) has stopped. The above configuration also makes it possible to detect, for example, the following abnormality: Although an electrolytic solution is being flown to the detecting section, a failure such as a breakage of the electrolyzing section causes the amount of electrolyzed water discharged from the electrolyzing section to be smaller than normal or even stops the discharge altogether.

Detecting a difference in electrical properties between the normal state (in which an electrolysis product [electrolyzed water] is being flown to the detector continuously) and a state in which an electrolytic substance (electrolytic solution) is being flown to the detector continuously) makes it possible to detect, for example, the following abnormality: Although an electrolytic substance (electrolytic solution) is being supplied normally, the electrolytic substance is electrolyzed insufficiently or is not electrolyzed.

The detection electrode(s) may at least partially double(s) as an electrode for electrolysis. This configuration is preferable because it reduces the parts count and cost for increased practicability. Including an inclined detection electrode pair is preferable because it increases the detectability. The electrolytic bath may preferably further include a cooling system, in particular a water-cooling system.

In a case where a detection electrode pair and an electrolysis electrode pair are to be included in the electrolyzing section in such a manner as to be parallel to each other, a holding section for holding the detection electrode pair and the electrolysis electrode pair may be formed to also serve as the electrolyzing section. This can reduce costs. It is preferable to further incline an electrolyzing section including a detection electrode pair and an electrolysis electrode pair that are parallel to each other. This increases both the detectability and electrolysis efficiency. Further including a water-cooling system stabilizes the respective temperatures of the detection electrodes and the electrolysis electrodes, and thereby provides a highly reliable detection system and electrolysis system. This is because the electrical properties and chemical reactions of a substance are typically temperature-dependent. Since a detector including electrodes utilizes electrical properties of a substance, and electrolysis utilizes an electrochemical reaction, a stable temperature is preferable, and including a cooling system is preferable.

The diluting section 20 serves to dilute, with water, electrolyzed water 18 produced by the electrolyzing section 5. This configuration makes it possible to produce electrolyzed water 18 having an appropriate effective chlorine concentration and to discharge such electrolyzed water 18 from the discharge opening 14.

Including the diluting section 20 to dilute electrolyzed water 18 produced by the electrolyzing section 5 makes it possible to increase the amount of electrolyzed water 18 produced. The water for the dilution is, for example, tap water. In a case where the diluting section 20 dilutes electrolyzed water 18 with tap water, an electromagnetic valve 23 may be connected to a faucet for supply of tap water to the diluting section 20. The electrolytic solution may alternatively be diluted before being electrolyzed. In this case, however, a mineral and/or the like contained in dilution water may be deposited on the electrolysis electrodes to decrease the electrolysis capability, or a component contained in dilution water may be electrolyzed to cause variations in the concentration, pH, and/or the like of the electrolyzed water. It is thus preferable to first electrolyze the electrolytic solution at the electrolyzing section and then dilute the electrolyzed water with tap water or the like as in the present embodiment.

The diluting section 20 may be configured such that electrolyzed water 18 produced by the electrolyzing section 5 and dilution water flow into each other. In this case, the diluting section 20 is configured such that the flow of electrolyzed water 18 produced by the electrolyzing section 5 joins a substantially horizontal flow of water. The diluting section 20 may also be configured such that electrolyzed water 18 produced by the electrolyzing section 5 is attracted to dilution water as a result of the Venturi effect caused by the flow of the dilution water.

The diluting section 20 may be configured to dilute electrolyzed water 18 in a dilution bath configured to receive the flow of electrolyzed water 18 produced by the electrolyzing section 5 and the flow of dilution water.

The electrolyzing apparatus 60 may be configured to be capable of changing the amount of dilution water used by the diluting section 20. The electrolyzing apparatus 60 may, for instance, include an electromagnetic valve 23 to be capable of changing the amount of water to be supplied to the diluting section 20. This configuration makes it possible to produce electrolyzed water 18 having any of different effective chlorine concentrations and to produce electrolyzed water 18 having an effective chlorine concentration customized for the use of the electrolyzed water 18.

The electrolyzing apparatus 60 may include a control section 6 to enable switching between electrolyzed water 18 having a normal concentration and electrolyzed water 18 having a high concentration. The control section 6 controls the electromagnetic valve 23 to switch concentrations for electrolyzed water 18. For example, electrolyzed water 18 having a normal concentration may have an effective chlorine concentration within a range of 15 ppm to 25 ppm, and electrolyzed water 18 having a high concentration may have an effective chlorine concentration within a range of 45 ppm to 55 ppm.

It is further preferable to include an electronically operated needle valve instead of a switch-type electromagnetic valve. An electronically operated needle valve is capable of changing the flow rate continuously, and thus makes it possible to continuously produce electrolyzed water with any high concentration from electrolyzed water having a minimum concentration at the time of a maximum flow rate.

The electrolyzing apparatus 60 may include a cooling section 54 configured to cool the electrolyzing section 5 with use of water for dilution of electrolyzed water 18. This configuration makes it possible to prevent the temperature of the electrolyzing section 5 from being increased by (i) heat generated as a result of electric resistance of the electrodes and/or solution resistance of the electrolytic solution and/or (ii) heat of various chemical reactions occurring in the electrolyzing section. The above configuration in turn makes it possible to prevent the concentration from varying as a result of a varying electrolysis efficiency and also prevent the respective lives of, for example, the electrolyzing section and the electrodes from being shortened by heat. The cooling section 54 may, for instance, include a cooling-water channel 53 through which dilution water flows. This configuration is preferable because it makes it possible to form a cooling-water channel together with the electrolyzing section as an integral part thereof and avoid the need for extra parts or attachment operation.

FIG. 12 is a schematic cross-sectional view of part of an electrolyzing apparatus 60 of Embodiment 6. The cooling-water channel 53 may be configured, for example, such that as illustrated in FIG. 12, tap water flows into the cooling-water channel 53 from a cooling-water inlet 56 positioned upstream of the diluting section 20, flows around the electrolysis electrode pair 1, and then flows out from a cooling-water outlet 57 positioned downstream of the diluting section 20. Forming a cooling-water channel 53 as described above makes it possible to use tap water for the dilution of electrolyzed water 18 to also cool the electrolyzing section 5.

The cooling-water channel 53 may be formed in the structural member 52 of the electrolyzing section 5 as illustrated in FIG. 12, or may be in the form of a pipe disposed around the electrolyzing section 5.

The electrolyzing apparatus 60 may include a stirring section 19. The stirring section 19 is configured to receive the flow of electrolyzed water 18 diluted by the diluting section 20 and cause the electrolyzed water 18 to flow out toward the discharge opening 14. Including such a stirring section 19 makes it possible to convert, into hypochlorous acids, chlorine gas that has not been converted by the electrolyzing section 5 or the diluting section 20 into hypochlorous acids. This in turn stabilizes, for example, the pH and effective chlorine concentration of electrolyzed water 18 discharged from the discharge opening 14, thereby making it possible to produce electrolyzed water 18 having a stable quality. The stirring section 19 may be a water tank in which a turbulent flow occurs or a stirring tank including a stirrer.

The stirring section 19 is not essential. However, with the stirring section 19, concentration becomes more stable. Furthermore, even if, by any change, the electrolyzing section 5, the diluting section 20, and the electrolyzed water channel failed to convert chlorine molecules into hypochlorous acids for some reason, the presence of the stirring section 19 facilitates conversion of chlorine molecules into hypochlorous acids. This prevents or reduces the release of chlorine gas and increases the concentration of hypochlorous acid. For instance, unconverted chlorine gas may be released in a case where the amount of chlorine gas produced at the electrolyzing section 5 is large relative to the amount of an aqueous solution in the electrolyzing section 5 and the electrolyzed water channel connecting the diluting section 20 and the discharge opening is very short. In such a case, the chlorine gas can be efficiently converted into hypochlorous acids by increasing the effective length of the electrolyzed water channel with the addition of the stirring section 19 and by increasing the surface area of bubble per unit amount of chlorine gas by breaking chlorine gas bubbles into smaller bubbles using turbulent flows in the stirring section 19, and thereby increasing the number of times the chlorine gas makes contact with dilution water molecules. This prevents or reduces the release of chlorine gas into the atmosphere and increases the effective chlorine concentration of electrolyzed water.

The discharge opening 14 may be connected to an outlet member 24. This makes it possible to supply the electrolyzed water 18 produced at the electrolyzing apparatus 60 to an outlet. By discharging the electrolyzed water 18 through the outlet into, for example, a bucket 51, it is possible to use the electrolyzed water 18 for various purposes. The outlet pipe 24 may be, for example, a flexible hose. Alternatively, the discharge opening 14 may serve as an outlet.

The control section 6 controls the electrolyzed water producing section 2. The control section 6 is connectable to the pump 8, the electrolysis electrode pair 1, the electromagnetic valve 23, and/or the detection electrode 26 via a signal line or a power supply line. The control section 6 may include the detecting section 25. The control section 6 may be connected to the detection electrode 25 or may be combined with the detection electrode 25 to constitute the detecting section 25.

The control section 6 is configured to be able to receive signals from an operation section 11. The operation section 11 may be constituted by manual operation buttons or a touchscreen. The operation section 11 may be connected to the control section 6 via a signal line or may be configured to remotely control the electrolyzing apparatus 60.

Electrolyzed Water Detecting Experiment

An electrolyzing section 5 as shown in (c) of FIG. 2 and FIG. 10 was prepared, and an experiment was conducted to detect, with the use of detection electrodes 26, electrolyzed water 18 produced with the use of electrolysis electrodes 1. Each detection electrode had an effective surface of 3 mm×3 mm, and the distance between the electrodes was 2 mm. The detection electrodes were made of the same material as that of which the electrolysis electrodes were made. FIGS. 13 and 14 show the results of the experiment.

FIG. 13 is a graph illustrating how current detected at the detection electrodes 26 changed when an electrolytic solution 12 supplied to the electrolyzing section 5 was electrolyzed with the use of the electrolysis electrodes 1 to obtain electrolyzed water 18. The graph demonstrates that, while the electrolyzed water 18 is produced normally, the current detected at the detection electrodes 26 fluctuates. The graph also demonstrates that the current detected may be small for a time period of not more than 5 seconds. This is presumably due to alternate passage by the detection electrodes 26 of (i) bubbles of chlorine gas and hydrogen gas generated as a result of electrolysis and (ii) electrolyzed water. This demonstrates that, by detecting whether or not such a fluctuation in detected current has occurred, it is possible to detect whether or not the electrolyzed water 18 is produced normally. It was also demonstrated that detecting a small current continuously for not less than 5 seconds indicates no supply of an electrolytic solution 12 to the electrolyzing section 5.

FIG. 14 is a graph illustrating how the current detected at the detection electrodes 26 changed when the supply of the electrolytic solution 12 to the electrolyzing section 5 stopped. When the supply of an electrolytic solution 12 stopped, the fluctuation of the current stopped being measured approximately 5 seconds after the stop of the supply. This shows that using the detection electrodes 26 makes it possible to detect a stop of the supply of an electrolytic solution 12 earlier.

A similar arrangement as described below may alternately be employed: as shown in (a) of FIG. 2 and FIG. 9, sensing electrodes are provided in, on, or at a pipe connecting the electrolyzing section and the discharge opening. An experiment was conducted with a pipe having an inner diameter of approximately 3 mm. The results of this experiment were similar to those described above.

It is preferable that a terminal post (post) of each detection electrode be positioned closer to the supply opening. With such an arrangement, the terminal portions and electrodes near the terminal portions are relatively less likely to be exposed to highly reactive gas or high-concentration electrolyzed water, and therefore less trouble occurs at the terminals and the points of contact between the terminals and the electrodes.

The detecting section included in an electrolyzing apparatus of the present invention is particularly suitable for an electrolyzing apparatus that includes inclined electrolysis electrodes. The inclined electrolysis electrodes provide improved electrolysis efficiency, but the concentration of electrolyzed water produced using such electrolysis electrodes readily changes rapidly in response to a change in supply conditions of the electrolytic solution. Therefore, the use of a detecting section of the present invention, which enables an early detection of an abnormality, is preferred. Furthermore, the sensing electrodes in an inclined state provide better sensitivity. Therefore, an electrolyzing apparatus including inclined electrolysis electrodes and inclined sensing electrodes provides high electrolysis performance and has a high degree of safety and reliability.

Effective Chlorine Concentration Measuring Experiment

An electrolyzing apparatus was prepared that was similar to the electrolyzing section 5 of the electrolyzing apparatus 60 illustrated in FIG. 1. An electrolysis experiment was conducted while the angle at which the electrode pair 1 was inclined relative to the vertical direction was changed. The electrode pair 1 included (i) an electrode (herein referred to as Ti electrode) made of a titanium plate with a long side of 8 cm, a short side of 3 cm, and a thickness of 1 mm and (ii) an electrode (herein referred to as Pt—Ir-coated Ti electrode) prepared by coating a titanium plate with a long side of 8 cm, a short side of 3 cm, and a thickness of 1 mm with platinum and iridium through a sintering process. The electrode pair 1 was fixed to a structural member 20 made of vinyl chloride resin in such a manner that the Ti electrode and the Pt—Ir-coated Ti electrode were substantially parallel to each other and separated from each other by a distance within a range of 1 mm to 5 mm. This prepared an electrolyzing apparatus. The electrode pair 1 was connected to a power source device in such a manner that the Ti electrode would serve as a negative electrode and that the Pt—Ir-coated Ti electrode would serve as a positive electrode.

An electrolyzing apparatus was installed while the angle at which the electrode pair 1 was inclined relative to the vertical direction was changed between approximately −80 degrees to approximately +80 degrees. A mixed aqueous solution of 2% to 4% sodium chloride and 0.3% to 0.4% hydrochloric acid was supplied to the electrolytic solution channel 7 from below at a fixed flow rate. The angle of inclination was (i) 0 degrees in a case where the electrode pair 1 extended vertically, (ii) a positive value in degree in a case where the electrode pair 1 was inclined in such a manner that the Pt—Ir-coated Ti electrode (positive electrode) was positioned higher, and (iii) a negative value in degree in a case where the electrode pair 1 was inclined in such a manner that the Pt—Ir-coated Ti electrode was positioned lower.

The power source device was operated to supply a constant current of 5 A to the electrode pair 1 for an electrolytic treatment of a mixed aqueous solution of sodium chloride and hydrochloric acid. The voltage applied was within a range of approximately 4 V to 5 V. The effective chlorine concentration (mg/L) of the aqueous solution after the electrolytic treatment was measured. The effective chlorine concentration was evaluated on the basis of color reaction caused by oxidation. The effective chlorine concentration of this Example thus shows a value indicative of the amount of all oxidative reactive substances.

FIG. 15 shows the measurement results of the experiment on the effective chlorine concentration. The effective chlorine concentration shown in FIG. 15 is for a case in which electrolyzed water was diluted with 1 L of water by normalization. The results show that inclining the electrode pair 1 in such a manner that the Pt—Ir-coated Ti electrode (positive electrode) was positioned higher successfully increased the effective chlorine concentration of an aqueous solution after an electrolytic treatment within a range of the inclination angle of 20 degrees to 80 degrees. The effective chlorine concentration was particularly high within a range of 50 degrees to 80 degrees.

The results also show that, on the other hand, inclining the electrode pair 1 in such a manner that the Pt—Ir-coated Ti electrode (positive electrode) was positioned lower decreased the effective chlorine concentration of an aqueous solution after an electrolytic treatment.

This proves that inclining the electrode pair 1 in such a manner that the positive electrode is positioned higher than the negative electrode increases the effective chlorine concentration of electrolyzed water produced.

When the inclination angle is less than about 0 degrees and has a negative value, even a slight change in inclination angle will result in a significant decrease in effective chlorine concentration. Therefore, it is preferable for practical use that the electrode pair 1 be inclined in such a manner that the inclination angle is greater than 0 degrees and has a positive value, i.e., in such a manner that the positive electrode is positioned higher than the negative electrode. This is because, with this arrangement, the effective chlorine concentration becomes high and stable with respect to variations in inclination angle of the electrode pair 1. The inclination angle is more preferably not less than 20 degrees and not more than 80 degrees.

REFERENCE SIGNS LIST

-   1: Electrolysis electrodes or electrolysis electrode pair -   2: Electrolyzed water producing section -   3: Positive electrode -   4: Negative electrode -   5: Electrolyzing section -   6: Control section, power source section -   7: Electrolytic solution tank -   8: Electrolytic solution pump -   10: Electrolytic solution supplying section -   11: Operation section -   12: Electrolytic solution -   14: Discharge opening -   18: Electrolyzed water -   19: Stirring section -   20: Diluting section -   23: Electromagnetic valve -   24: Outlet member -   25: Detecting section -   26: Detection electrode -   28: Housing -   41: Tap water inlet -   42: Electrolytic solution inlet -   51: Bucket -   52: Structural member -   53: Cooling water channel -   54: Cooling section -   56: Cooling water inlet -   57: Cooling water outlet -   60: Electrolyzing apparatus 

1. An electrolyzing apparatus comprising an electrolyzing section and a detecting section, the electrolyzing section being configured to receive an electrolytic substance, electrolyze the electrolytic substance to obtain an electrolysis product, and discharge the electrolysis product, the electrolyzing section including electrolysis electrodes, and the detecting section including a detection electrode configured to measure an electrical property of either one of or a mixture of both of the electrolytic substance and the electrolysis product and being configured to detect a decrease in amount of the electrolytic substance received by the electrolyzing section or a decrease in amount of the electrolysis product discharged from the electrolyzing section.
 2. The electrolyzing apparatus according to claim 1, wherein the detection electrode is positioned higher than the electrolysis electrodes.
 3. The electrolyzing apparatus according to claim 1, wherein the detection electrode is positioned upstream of the electrolysis electrodes.
 4. The electrolyzing apparatus according to claim 1, wherein the detection electrode is disposed in, on, or at the electrolyzing section or a pipe connected to the electrolyzing section so as to be downstream of the electrolysis electrodes.
 5. The electrolyzing apparatus according to claim 1, wherein the detection electrode includes at least one pair of electrodes, and one of the at least one pair of electrodes of the detection electrode is electrically connected to either one of the electrolysis electrodes.
 6. The electrolyzing apparatus according to claim 1, wherein the detection electrode includes at least one pair of electrodes, and one of the at least one pair of electrodes of the detection electrode is integral with either one of the electrolysis electrodes.
 7. The electrolyzing apparatus according to claim 1, wherein the electrolysis electrodes and the detection electrode are inclined.
 8. The electrolyzing apparatus according to claim 1, wherein the electrolytic substance is an electrolytic solution, and the electrolyzing section is configured to electrolyze the electrolytic solution to produce electrolyzed water containing hypochlorous acids.
 9. The electrolyzing apparatus according to claim 8, wherein the detection electrode is arranged to measure an electrical property of a gas-liquid mixture fluid composed of the electrolyzed water and a gas which are produced from electrolysis of the electrolytic solution.
 10. An electrolyzing apparatus comprising an electrolyzing section and a detecting section, the electrolyzing section being configured to electrolyze an electrolytic substance, the electrolyzing section including electrolysis electrodes, and the detecting section being configured to detect, on a basis of an amount of change over time in a relationship between a current through the electrolysis electrodes and a voltage across the electrolysis electrodes, a decrease in amount of the electrolytic substance received by the electrolyzing section.
 11. The electrolyzing apparatus according to claim 10, wherein the detecting section is configured to detect, on the basis of a derivative value of the amount of change in the voltage across the electrolysis electrodes or on the basis of a derivative value of the amount of change in the current through the electrolysis electrodes, a decrease in amount of the electrolytic substance received by the electrolyzing section.
 12. The electrolyzing apparatus according to claim 10, wherein the electrolytic substance is an electrolytic solution, and the electrolyzing section is configured to electrolyze the electrolytic solution to produce electrolyzed water containing hypochlorous acids.
 13. The electrolyzing apparatus according to claim 12, further comprising an electrolytic solution supplying section, the electrolytic solution supplying section being configured to supply the electrolytic solution from a tank to the electrolyzing section.
 14. The electrolyzing apparatus according to claim 12, further comprising a diluting section configured to dilute the electrolyzed water produced by the electrolyzing section.
 15. The electrolyzing apparatus according to claim 14, further comprising a cooling section configured to cool the electrolyzing section, the cooling section being configured to cool the electrolyzing section with water that is for use in diluting the electrolyzed water.
 16. The electrolyzing apparatus according to claim 12, wherein the electrolytic solution is an aqueous solution containing an acidic substance and an alkali metal chloride.
 17. The electrolyzing apparatus according to claim 16, wherein the acidic substance is hydrochloric acid, and the alkali metal chloride is at least one of sodium chloride and potassium chloride. 